1. Field of the Invention
The invention relates to a contact clip for an insulated, multi-strand electric cable, in particular, a shape-coded shaped cable, comprised of two clip parts engaging one another, wherein one clip part has a receptacle for the position-correct placement of the cable and the other clip part has at least one contact pin correlated with one strand of the cable, respectively, which in the mounted state of the clip parts, pierces the insulation of the cable and is positioned electrically contacting within the strand of the cable in the pierced position, wherein the contact pins are positioned transversely to the longitudinal direction of the cable adjacent to and at a spacing from one another which spacing corresponds approximately to the spacing of the strands.
2. Description of the Related Art
Shape-coded shaped cables are used as bus cables or energy-supply cables in machine controls in order to connect actuating devices (solenoid valves and the like) and sensors with an interface. These shaped cables must withstand high mechanical loading and must be resistant against soiling, acids, solvents and the like so that a correspondingly resistant insulation is selected. The shaped cables, which are usually configured as flat cables, are difficult to contact because of their resistant insulation so that piercing is employed. Accoridng to this piercing technology, the shaped cable is pressed onto contact blades which cut through the insulation and penetrate into the copper core of the cable strands in order to produce electrical contacting. This requires that a terminal-correct contacting be realized in order to ensure proper electrical function. In practice, it was found that when installing shaped cables the cables are often introduced into the piercing connector in a reversed position. In order to provide a position-correct insertion of the cable, it was therefore necessary to provide additional loops; this is cumbersome, uses up installation space, and greatly impedes a search for errors.
It is an object of the present invention to provide a piercing contact clip which ensures, independent of the position of the cable to be connected, a terminal-correct connection, i.e., the proper terminals are connected with one another.
In accordance with the present invention, this is achieved in that the receptacle is configured to be wider than the cable in a direction transversely to the longitudinal direction of the cable, in that a fitting member is inserted into the receptacle which determines the lateral position of the cable in the receptacle, and in that in the other clip part an additional contact pin is provided which is located transversely to the longitudinal direction of the cable at a spacing, corresponding approximately to the spacing between the strands, to the neighboring contact pin, and, depending on the lateral position of the cable within the receptacle, either engages the strand of the cable or engages the fitting member.
It is important in this connection that the receptacle is wider transversely to the longitudinal direction of the cable than the cable itself in order to be able to change the lateral positioning of the cable in the receptacle depending on the position of the incoming cable. For this purpose, a fitting member is provided which, as a function of the position of the incoming cable, is arranged either at one or the other lateral edge of the receptacle so that the cable can be displaced by the width of the fitting member transversely to the longitudinal direction of the cable. In accordance with the displacement of the cable in the receptacle, the other clip part is provided with an additional contact pin which is positioned in a direction transversely to the longitudinal direction of the cable at a spacing, corresponding approximately to the spacing of the strands, relative to the neighboring contact pin so that depending on the lateral position of the cable in the receptacle this contact pin engages either one strand of the cable or the fitting member.
Depending on the position of the incoming cable, either one or the other outer contact pin are used for contacting the strand in the incoming cable, wherein the contact pin not contacting the strand dead-ends.
Preferably, the arrangement is such that a central row of contacts is positioned in a plane which symmetrically divides the receptacle in the longitudinal direction of the cable. The positional change of the cable within the receptacle corresponds thus always to the spacing of the strands of the cable relative to the center, wherein the central row of contacts in this way always contacts the same strand in the receptacle independent of the position of the cable.
Preferably, the cable is a dual-strand cable having correlated therewith three contact pins arranged transversely to the longitudinal direction of the cable adjacent to one another. The cable is then positioned in a first position at a first lateral edge of the receptacle and in the other position at the second lateral edge of the receptacle so that the cable can be positioned in a first position and a second position that are rotated by 180 degrees relative to one another about the central contact pin.
The contact pins are preferably contact blades having a cutting blade aligned approximately in the longitudinal direction of the cable and centrally cutting into the core of the cable strand.
In order to ensure, independent of the position of the cable in the receptacle, a terminal-correct connection of the contact clip, the outer contact pins are connected electrically with one another.
In order to also satisfy the strict requirements of upper-level safety classes, it is preferably provided that the fitting member is embodied as a sealing device so that the fitting member surrounds expediently, preferably completely, the cable. The fitting member itself thus forms a seal surrounding the cable so that the contact area of the piercing blade is properly sealed against the environment.
The shaped cable can extend through the contact clip wherein the contact clip itself is an electrical connector between the end pieces of the shaped cables or of cables that extend adjacent and parallel to one another. Also, the contact clip according to the invention can be provided with a plug connector for which purpose, for example, the plug connector is arranged on one or the other clip part. Preferably, the plug connector or the like is provided on the clip part which also supports the contact pins (contact blades).